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EP0341977A2
Expired / Lapsed
EP
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Composites from wet formed blends of glass and thermoplastic fibers
Assignee: Virginia Tech Foundation Inc
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Filing: 1989-05-09
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Granted: —
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Expires: 2009-05-09
Abstract
Abstract A process for forming a self-supporting preform layer of a homogeneous blend of relatively long glass staple length fibers and wettable fine denier staple length thermoplastic filaments wherein a neutral pH aqueous slurry of the glass fibers and filaments are formed into a mat using conventional papermaking equipment. In the preferred process the wettable thermoplastic filaments are dispersed first in the water then followed by the addition of the glass fibers. The self-supporting preform when converted into a molded composite structure results in a substantially void-free structure of individual glass fibers embedded in a thermoplastic resin matrix.
Inventors
- 👤 Gregory Paul Weeks
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:09
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/04; C08J5/06; C08J5/08; D; D21; D21H; D21H15/00; D21H15/02; D21H15/06; B; B29; B29B; B29B15/00; B29B15/08; B29B15/10; B29B15/12; B29C; B29C70/00; B29C70/04; B29C70/28; D21H13/00; D21H13/36; D21H13/38; D21H13/40; B29K; B29K2301/00; B29K2301/12; B29K2309/00; B29K2309/08
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
165 words
A method for forming a preform layer composed of individual glass staple filaments intimately mixed with a thermoplastic fiber, comprising: dispersing in an agitated, aqueous neutral pH solution substantially free of other constituents, a plurality of 0.5 to 20 denier, 1 mm to 5 cm staple length thermoplastic fibers and a quantity of wet chopped glass strand to the agitated solution, said chopped glass strand consisting of bundles of numerous aligned glass fibers of length 1 cm to 8 cm and diameter 5 to 50 microns coated and adhered to each other with sufficient integrity to permit handling during normal processing; continuing agitation of the solution to substantially disperse the glass fiber bundles forming a homogeneous filamentary slurry of thermoplastic and glass fibers, feeding the slurry to a screen in a layer, removing water from the layer; drying the layer, further heating the layer to a temperature to thermally bond the thermoplastic component fiber; and then cooling the layer to form a self-supporting preform layer.
Claim 2
Independent Claim
165 words
A method for forming a preform layer composed of individual glass staple filaments intimately mixed with a thermoplastic fiber, comprising: dispersing in an agitated, aqueous neutral pH solution substantially free of other constituents, a plurality of 0.5 to 20 denier, 1 mm to 5 cm staple length thermoplastic fibers and a quantity of wet chopped glass strand to the agitated solution, said chopped glass strand consisting of bundles of numerous aligned glass fibers of length 1 cm to 8 cm and diameter 5 to 50 microns coated and adhered to each other with sufficient integrity to permit handling during normal processing; continuing agitation of the solution to substantially disperse the glass fiber bundles forming a homogeneous filamentary slurry of thermoplastic and glass fibers, feeding the slurry to a screen in a layer, removing water from the layer; drying the layer, further heating the layer to a temperature to thermally bond the thermoplastic component fiber; and then cooling the layer to form a self-supporting preform layer.
Claim 3
Dependent Claim
23 words
The method as defined in claim 1, wherein said thermoplastic fibers are added to the aqueous solution first followed by the glass fibers.
Claim 4
Dependent Claim
23 words
The method as defined in claim 1, wherein said glass fibers are added to the aqueous solution first followed by the thermoplastic fibers.
Claim 5
Dependent Claim
17 words
The method as defined in claim 1, wherein said thermoplastic and said glass fibers are added simultaneously.
Claim 6
Independent Claim
46 words
The method as defined in claims 1, 2, 3 or 4 wherein said thermoplastic fibers have a coating of a dispersing aid on their surfaces, and at least a portion of said fibers are coated with a lower melting polymer of substantially the same chemical composition.
Claim 7
Dependent Claim
24 words
The method of claim 5 wherein said dispersing aid is a condensation product of tallow alcohols with polyethylene oxides and low molecular weight polyesters.
Claim 8
Dependent Claim
109 words
A self-supporting preform layer of individual reinforcing glass fibers intimately mixed with thermoplastic fibers, comprising: an intimate homogeneous blend consisting of 10 to 70 percent by weight glass staple fibers substantially dispersed as individual filaments randomly arrayed in the plane of the layer and having on their surface a sizing agent, comprising a coupling agent and a film forming agent, said glass fibers having a length of 1 cm to 8 cm and a diameter of 5 to 50 microns, intimately mixed with 90 to 30 percent by weight thermoplastic staple fibers substantially dispersed as individual filaments from 0.5-20 denier having a length of 1.0 mm to 5 cm.
Claim 9
Dependent Claim
109 words
A self-supporting preform layer of individual reinforcing glass fibers intimately mixed with thermoplastic fibers, comprising: an intimate homogeneous blend consisting of 10 to 70 percent by weight glass staple fibers substantially dispersed as individual filaments randomly arrayed in the plane of the layer and having on their surface a sizing agent, comprising a coupling agent and a film forming agent, said glass fibers having a length of 1 cm to 8 cm and a diameter of 5 to 50 microns, intimately mixed with 90 to 30 percent by weight thermoplastic staple fibers substantially dispersed as individual filaments from 0.5-20 denier having a length of 1.0 mm to 5 cm.
Claim 10
Dependent Claim
46 words
The preform layer of claim 7, wherein a portion of said thermoplastic fibers are coated with a lower melting polymer of substantially the same chemical composition as said thermoplastic fibers, said portion forming bonds between the remainder of the themoplastic fibers and said chopped glass fibers.
Claim 11
Dependent Claim
15 words
The preform layer of claim 7 or 8, wherein said thermoplastic fiber is a polyamide.
Claim 12
Dependent Claim
14 words
The preform layer of claim 7 or 8, wherein said thermoplastic fiber is polypropylene.
Claim 13
Dependent Claim
21 words
The preform layer of claim 7 or 8, wherein said thermoplastic fiber is poly(ethylene terephthalate) containing a precompounded antioxidant and toughner.
Claim 14
Dependent Claim
17 words
The preform layer of claim 8, wherein said lower melting polymer is a copolymer of poly(ethylene terephthalate).
Claim 15
Dependent Claim
22 words
A composite formed from at least one preform layer of any one of Claims 7 to 12, said composite being substantially void-free.
References Cited (Backward Citations)
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